The Met Office has issued a weather warning for thunderstorm from Thursday this week.
The yellow weather warning will make its way through the way the UK, moving from the western parts of the country to the eastern side on Saturday.
It is in place in the south west from 4pm on Thursday to 9am on Friday.
It is in contrast to today's bright, sunny weather, when temperatures are expected to go over 30C.
The Met Office said in a statement: "Whilst many places will be dry or see little rain, thunderstorms may cause flooding and disruption in a few places.
"There is a small chance that homes and businesses could be flooded quickly, with damage to some buildings from floodwater, lightning strikes, hail or strong winds.
"Where flooding or lightning strikes occur, there is a chance of delays and some cancellations to train and bus services."
The Met Office said that spray and sudden flooding could lead to difficult driving conditions and some road closures, adding there was a small chance that some communities become cut off by flooded roads.
"There is a slight chance that power cuts could occur and other services to some homes and businesses could be lost," the statement added.
